1 /*
   2  * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.java2d.opengl;
  27 
  28 import sun.awt.util.ThreadGroupUtils;
  29 import sun.java2d.pipe.RenderBuffer;
  30 import sun.java2d.pipe.RenderQueue;
  31 
  32 import static sun.java2d.pipe.BufferedOpCodes.*;
  33 import java.security.AccessController;
  34 import java.security.PrivilegedAction;
  35 
  36 /**
  37  * OGL-specific implementation of RenderQueue.  This class provides a
  38  * single (daemon) thread that is responsible for periodically flushing
  39  * the queue, thus ensuring that only one thread communicates with the native
  40  * OpenGL libraries for the entire process.
  41  */
  42 public class OGLRenderQueue extends RenderQueue {
  43 
  44     private static OGLRenderQueue theInstance;
  45     private final QueueFlusher flusher;
  46 
  47     private OGLRenderQueue() {
  48         /*
  49          * The thread must be a member of a thread group
  50          * which will not get GCed before VM exit.
  51          */
  52         flusher = AccessController.doPrivileged((PrivilegedAction<QueueFlusher>) QueueFlusher::new);
  53     }
  54 
  55     /**
  56      * Returns the single OGLRenderQueue instance.  If it has not yet been
  57      * initialized, this method will first construct the single instance
  58      * before returning it.
  59      */
  60     public static synchronized OGLRenderQueue getInstance() {
  61         if (theInstance == null) {
  62             theInstance = new OGLRenderQueue();
  63         }
  64         return theInstance;
  65     }
  66 
  67     /**
  68      * Flushes the single OGLRenderQueue instance synchronously.  If an
  69      * OGLRenderQueue has not yet been instantiated, this method is a no-op.
  70      * This method is useful in the case of Toolkit.sync(), in which we want
  71      * to flush the OGL pipeline, but only if the OGL pipeline is currently
  72      * enabled.  Since this class has few external dependencies, callers need
  73      * not be concerned that calling this method will trigger initialization
  74      * of the OGL pipeline and related classes.
  75      */
  76     public static void sync() {
  77         if (theInstance != null) {
  78             theInstance.lock();
  79             try {
  80                 theInstance.ensureCapacity(4);
  81                 theInstance.getBuffer().putInt(SYNC);
  82                 theInstance.flushNow();
  83             } finally {
  84                 theInstance.unlock();
  85             }
  86         }
  87     }
  88 
  89     /**
  90      * Disposes the native memory associated with the given native
  91      * graphics config info pointer on the single queue flushing thread.
  92      */
  93     public static void disposeGraphicsConfig(long pConfigInfo) {
  94         OGLRenderQueue rq = getInstance();
  95         rq.lock();
  96         try {
  97             // make sure we make the context associated with the given
  98             // GraphicsConfig current before disposing the native resources
  99             OGLContext.setScratchSurface(pConfigInfo);
 100 
 101             RenderBuffer buf = rq.getBuffer();
 102             rq.ensureCapacityAndAlignment(12, 4);
 103             buf.putInt(DISPOSE_CONFIG);
 104             buf.putLong(pConfigInfo);
 105 
 106             // this call is expected to complete synchronously, so flush now
 107             rq.flushNow();
 108         } finally {
 109             rq.unlock();
 110         }
 111     }
 112 
 113     /**
 114      * Returns true if the current thread is the OGL QueueFlusher thread.
 115      */
 116     public static boolean isQueueFlusherThread() {
 117         return (Thread.currentThread() == getInstance().flusher.thread);
 118     }
 119 
 120     public void flushNow() {
 121         // assert lock.isHeldByCurrentThread();
 122         try {
 123             flusher.flushNow();
 124         } catch (Exception e) {
 125             System.err.println("exception in flushNow:");
 126             e.printStackTrace();
 127         }
 128     }
 129 
 130     public void flushAndInvokeNow(Runnable r) {
 131         // assert lock.isHeldByCurrentThread();
 132         try {
 133             flusher.flushAndInvokeNow(r);
 134         } catch (Exception e) {
 135             System.err.println("exception in flushAndInvokeNow:");
 136             e.printStackTrace();
 137         }
 138     }
 139 
 140     private native void flushBuffer(long buf, int limit);
 141 
 142     private void flushBuffer() {
 143         // assert lock.isHeldByCurrentThread();
 144         int limit = buf.position();
 145         if (limit > 0) {
 146             // process the queue
 147             flushBuffer(buf.getAddress(), limit);
 148         }
 149         // reset the buffer position
 150         buf.clear();
 151         // clear the set of references, since we no longer need them
 152         refSet.clear();
 153     }
 154 
 155     private class QueueFlusher implements Runnable {
 156         private boolean needsFlush;
 157         private Runnable task;
 158         private Error error;
 159         private final Thread thread;
 160 
 161         public QueueFlusher() {
 162             String name = "Java2D Queue Flusher";
 163             thread = new Thread(ThreadGroupUtils.getRootThreadGroup(),
 164                                 this, name, 0, false);
 165             thread.setDaemon(true);
 166             thread.setPriority(Thread.MAX_PRIORITY);
 167             thread.start();
 168         }
 169 
 170         public synchronized void flushNow() {
 171             // wake up the flusher
 172             needsFlush = true;
 173             notify();
 174 
 175             // wait for flush to complete
 176             while (needsFlush) {
 177                 try {
 178                     wait();
 179                 } catch (InterruptedException e) {
 180                 }
 181             }
 182 
 183             // re-throw any error that may have occurred during the flush
 184             if (error != null) {
 185                 throw error;
 186             }
 187         }
 188 
 189         public synchronized void flushAndInvokeNow(Runnable task) {
 190             this.task = task;
 191             flushNow();
 192         }
 193 
 194         public synchronized void run() {
 195             boolean timedOut = false;
 196             while (true) {
 197                 while (!needsFlush) {
 198                     try {
 199                         timedOut = false;
 200                         /*
 201                          * Wait until we're woken up with a flushNow() call,
 202                          * or the timeout period elapses (so that we can
 203                          * flush the queue periodically).
 204                          */
 205                         wait(100);
 206                         /*
 207                          * We will automatically flush the queue if the
 208                          * following conditions apply:
 209                          *   - the wait() timed out
 210                          *   - we can lock the queue (without blocking)
 211                          *   - there is something in the queue to flush
 212                          * Otherwise, just continue (we'll flush eventually).
 213                          */
 214                         if (!needsFlush && (timedOut = tryLock())) {
 215                             if (buf.position() > 0) {
 216                                 needsFlush = true;
 217                             } else {
 218                                 unlock();
 219                             }
 220                         }
 221                     } catch (InterruptedException e) {
 222                     }
 223                 }
 224                 try {
 225                     // reset the throwable state
 226                     error = null;
 227                     // flush the buffer now
 228                     flushBuffer();
 229                     // if there's a task, invoke that now as well
 230                     if (task != null) {
 231                         task.run();
 232                     }
 233                 } catch (Error e) {
 234                     error = e;
 235                 } catch (Exception x) {
 236                     System.err.println("exception in QueueFlusher:");
 237                     x.printStackTrace();
 238                 } finally {
 239                     if (timedOut) {
 240                         unlock();
 241                     }
 242                     task = null;
 243                     // allow the waiting thread to continue
 244                     needsFlush = false;
 245                     notify();
 246                 }
 247             }
 248         }
 249     }
 250 }